Re: [PATCH V6 16/21] soc/tegra: pmc: Add pmc wake support for tegra210

Dmitry Osipenko
2019-07-23T03:04:02Z

23.07.2019 4:52, Sowjanya Komatineni пишет:
>
> On 7/22/19 6:41 PM, Dmitry Osipenko wrote:
>> 23.07.2019 4:08, Dmitry Osipenko пишет:
>>> 23.07.2019 3:58, Dmitry Osipenko пишет:
>>>> 21.07.2019 22:40, Sowjanya Komatineni пишет:
>>>>> This patch implements PMC wakeup sequence for Tegra210 and defines
>>>>> common used RTC alarm wake event.
>>>>>
>>>>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>>>>> ---
>>>>> drivers/soc/tegra/pmc.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++
>>>>> 1 file changed, 111 insertions(+)
>>>>>
>>>>> diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
>>>>> index 91c84d0e66ae..c556f38874e1 100644
>>>>> --- a/drivers/soc/tegra/pmc.c
>>>>> +++ b/drivers/soc/tegra/pmc.c
>>>>> @@ -57,6 +57,12 @@
>>>>> #define PMC_CNTRL_SYSCLK_OE BIT(11) /* system clock enable */
>>>>> #define PMC_CNTRL_SYSCLK_POLARITY BIT(10) /* sys clk polarity */
>>>>> #define PMC_CNTRL_MAIN_RST BIT(4)
>>>>> +#define PMC_CNTRL_LATCH_WAKEUPS BIT(5)
>>> Please follow the TRM's bits naming.
>>>
>>> PMC_CNTRL_LATCHWAKE_EN
>>>
>>>>> +#define PMC_WAKE_MASK 0x0c
>>>>> +#define PMC_WAKE_LEVEL 0x10
>>>>> +#define PMC_WAKE_STATUS 0x14
>>>>> +#define PMC_SW_WAKE_STATUS 0x18
>>>>>
>>>>> #define DPD_SAMPLE 0x020
>>>>> #define DPD_SAMPLE_ENABLE BIT(0)
>>>>> @@ -87,6 +93,11 @@
>>>>>
>>>>> #define PMC_SCRATCH41 0x140
>>>>>
>>>>> +#define PMC_WAKE2_MASK 0x160
>>>>> +#define PMC_WAKE2_LEVEL 0x164
>>>>> +#define PMC_WAKE2_STATUS 0x168
>>>>> +#define PMC_SW_WAKE2_STATUS 0x16c
>>>>> +
>>>>> #define PMC_SENSOR_CTRL 0x1b0
>>>>> #define PMC_SENSOR_CTRL_SCRATCH_WRITE BIT(2)
>>>>> #define PMC_SENSOR_CTRL_ENABLE_RST BIT(1)
>>>>> @@ -1922,6 +1933,55 @@ static const struct irq_domain_ops tegra_pmc_irq_domain_ops = {
>>>>> .alloc = tegra_pmc_irq_alloc,
>>>>> };
>>>>>
>>>>> +static int tegra210_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>>>>> +{
>>>>> + struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>>>>> + unsigned int offset, bit;
>>>>> + u32 value;
>>>>> +
>>>>> + if (data->hwirq == ULONG_MAX)
>>>>> + return 0;
>>>>> +
>>>>> + offset = data->hwirq / 32;
>>>>> + bit = data->hwirq % 32;
>>>>> +
>>>>> + /*
>>>>> + * Latch wakeups to SW_WAKE_STATUS register to capture events
>>>>> + * that would not make it into wakeup event register during LP0 exit.
>>>>> + */
>>>>> + value = tegra_pmc_readl(pmc, PMC_CNTRL);
>>>>> + value |= PMC_CNTRL_LATCH_WAKEUPS;
>>>>> + tegra_pmc_writel(pmc, value, PMC_CNTRL);
>>>>> + udelay(120);
>>>> Why it takes so much time to latch the values? Shouldn't some status-bit
>>>> be polled for the completion of latching?
>>>>
>>>> Is this register-write really getting buffered in the PMC?
>>>>
>>>>> + value &= ~PMC_CNTRL_LATCH_WAKEUPS;
>>>>> + tegra_pmc_writel(pmc, value, PMC_CNTRL);
>>>>> + udelay(120);
>>>> 120 usecs to remove latching, really?
>>>>
>>>>> + tegra_pmc_writel(pmc, 0, PMC_SW_WAKE_STATUS);
>>>>> + tegra_pmc_writel(pmc, 0, PMC_SW_WAKE2_STATUS);
>>>>> +
>>>>> + tegra_pmc_writel(pmc, 0, PMC_WAKE_STATUS);
>>>>> + tegra_pmc_writel(pmc, 0, PMC_WAKE2_STATUS);
>>>>> +
>>>>> + /* enable PMC wake */
>>>>> + if (data->hwirq >= 32)
>>>>> + offset = PMC_WAKE2_MASK;
>>>>> + else
>>>>> + offset = PMC_WAKE_MASK;
>>>>> +
>>>>> + value = tegra_pmc_readl(pmc, offset);
>>>>> +
>>>>> + if (on)
>>>>> + value |= 1 << bit;
>>>>> + else
>>>>> + value &= ~(1 << bit);
>>>>> +
>>>>> + tegra_pmc_writel(pmc, value, offset);
>>>> Why the latching is done *before* writing into the WAKE registers? What
>>>> it is latching then?
>>> I'm looking at the TRM doc and it says that latching should be done
>>> *after* writing to the WAKE_MASK / LEVEL registers.
>>>
>>> Secondly it says that it's enough to do:
>>>
>>> value = tegra_pmc_readl(pmc, PMC_CNTRL);
>>> value |= PMC_CNTRL_LATCH_WAKEUPS;
>>> tegra_pmc_writel(pmc, value, PMC_CNTRL);
>>>
>>> in order to latch. There is no need for the delay and to remove the
>>> "LATCHWAKE_EN" bit, it should be a oneshot action.
>> Although, no. TRM says "stops latching on transition from 1
>> to 0 (sequence - set to 1,set to 0)", so it's not a oneshot action.
>>
>> Have you tested this code at all? I'm wondering how it happens to work
>> without a proper latching.
> Yes, ofcourse its tested and this sequence to do transition is
> recommendation from Tegra designer.
> Will check if TRM doesn't have update properly or will re-confirm
> internally on delay time...
>
> On any of the wake event PMC wakeup happens and WAKE_STATUS register
> will have bits set for all events that triggered wake.
> After wakeup PMC doesn't update SW_WAKE_STATUS register as per PMC design.
> SW latch register added in design helps to provide a way to capture
> those events that happen right during wakeup time and didnt make it to
> SW_WAKE_STATUS register.
> So before next suspend entry, latching all prior wake events into SW
> WAKE_STATUS and then clearing them.

I'm now wondering whether the latching cold be turned ON permanently
during of the PMC's probe, for simplicity.

> LATCHWAKE_EN - When set, enables latching and stops latching on
> transition from 1 to 0
> There is recommendation of min 120uSec for this transition to stop
> latching. Will double-check why 120uSec

Yes, please check.

>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> static int tegra186_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>>>>> {
>>>>> struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>>>>> @@ -1954,6 +2014,49 @@ static int tegra186_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
>>>>> return 0;
>>>>> }
>>>>>
>>>>> +static int tegra210_pmc_irq_set_type(struct irq_data *data, unsigned int type)
>>>>> +{
>>>>> + struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
>>>>> + unsigned int offset, bit;
>>>>> + u32 value;
>>>>> +
>>>>> + if (data->hwirq == ULONG_MAX)
>>>>> + return 0;
>>>>> +
>>>>> + offset = data->hwirq / 32;
>>>>> + bit = data->hwirq % 32;
>>>>> +
>>>>> + if (data->hwirq >= 32)
>>>>> + offset = PMC_WAKE2_LEVEL;
>>>>> + else
>>>>> + offset = PMC_WAKE_LEVEL;
>>>>> +
>>>>> + value = tegra_pmc_readl(pmc, offset);
>>>>> +
>>>>> + switch (type) {
>>>>> + case IRQ_TYPE_EDGE_RISING:
>>>>> + case IRQ_TYPE_LEVEL_HIGH:
>>>>> + value |= 1 << bit;
>>>>> + break;
>>>>> +
>>>>> + case IRQ_TYPE_EDGE_FALLING:
>>>>> + case IRQ_TYPE_LEVEL_LOW:
>>>>> + value &= ~(1 << bit);
>>>>> + break;
>>>>> +
>>>>> + case IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING:
>>>>> + value ^= 1 << bit;
>>>>> + break;
>>>>> +
>>>>> + default:
>>>>> + return -EINVAL;
>>>>> + }
>>>>> +
>>>>> + tegra_pmc_writel(pmc, value, offset);
>>>> Shouldn't the WAKE_LEVEL be latched as well?
> WAKE_LEVELs dont need any latch as they are the levels SW sets for wake
> trigger and they are not status

Okay.

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